1. Field of the Invention
The present invention relates to a method of packing powder with a grain size as small as 20 xcexcm or less in a container having a small mouth or a small volume or in a container unable to be packed with powder by gravity, and an apparatus therefore. More particularly, the present invention relates to a method of directly packing toner in a toner cartridge for an image forming apparatus or a developing unit included in the image forming apparatus, and an apparatus therefor.
2. Description of the Background Art
A rotary valve, a screw feeder and an auger, for example, belong to a family of members customarily used to pack a container with powder. After a container has been positioned beneath such a packing member, the packing member is operated to increase the bulk density of powder and delivers the powder into the container. This kind of packing scheme can efficiently pack the powder in the container having a preselected volume.
Japanese Patent Laid-Open Publication No. 9-193902, for example, discloses a powder packing method using a gas for fluidizing powder. Specifically, after the gas has been sent into the powder stored in a tank for fluidizing it, the powder is conveyed from the tank to the vicinity of a container via a conveying tube. A gas discharging tube releases the gas from the powder and then introduces the powder into the container.
The powder packing method taught in the above document has the following problems left unsolved. The conveying tube and gas discharging tube must be accurately coaxial with each other and are therefore difficult to assemble and make the entire assembly too heavy to carry. Moreover, the powder packing method is workable so long as the container has a large mouth diameter. However, if the container has a small mouth diameter or a sophisticated configuration, then the powder delivered from a packing apparatus to the container cannot be easily replaced with air inside the container. As a result, it is likely that the powder introduced into the container is blown out of the container via the mouth or obstructed by structural members, which may exist in the container.
The conventional powder packing methods have another problem when applied to a copier, printer or similar image forming apparatus using toner and situated at an ordinary office as one of OA (Office Automation) equipment. Specifically, when the toner is directly replenished to a toner bottle or a developing unit mounted on the image forming apparatus, the toner fly about in the office or, if successfully replenished, contains much air and is therefore low packing density.
It is an object of the present invention to provide a powder packing method capable of packing powder even in a container having a small mouth diameter or a sophisticated configuration, and an apparatus therefor.
It is another object of the present invention to provide a powder packing method capable of releasing air from powder packed in a container to thereby implement dense packing without any dust with a handy, easy-to-operated construction, and an apparatus therefor.
It is a further object of the present invention to provide a powder packing method allowing any one to pack a container with powder at any place without smear, and an apparatus therefor.
In accordance with the present invention, a method of packing a container with powder includes the steps of inserting a nozzle for introducing powder fluidized by a gas into a container into the container, and packing the container with the powder with the end of the nozzle being surrounded by powder present in the container.
Also, in accordance with the present invention, a powder packing apparatus includes a fluidizing device capable of being hermetically closed and formed with a gas inlet for receiving a gas for fluidization. A nozzle includes a hole for sending out the gas and is capable of hermetically closing the mouth of a container. A powder conveying path provides fluid communication between the fluidizing device and the nozzle. A first and a second filter are respectively positioned at the gas inlet of the fluidizing device and the hole of the nozzle, and each passes the gas, but filters out powder. The powder fluidized is confined between the fluidizing device and the container. The gas inlet of the fluidizing device has an area 1.002 times or more greater than the area of the hole of the nozzle for thereby causing the gas to flow at a higher rate through the hole than through the gas inlet. In this configuration, the powder is naturally introduced from the fluidizing device into the container via the powder conveying path and nozzle.